What Is The Most Romantic Song That You Have Ever Listen To?

How about "Extreme-More than words"?

There are so many, but two that come to mind are Gato Barbieri's Europa, and Van Morrison's Wild Honey

Too many to list, so 3 suggestions. 1st is from the '60s but I didn't hear it 'til 2 years ago. 2nd is very recent. 3rd is classic bossa nova.  All 3 are quite romantic (and blue):

Irma Thomas/"Anyone Who Knows What Love Is (Will Understand)"
https://www.youtube.com/watch?v=wPT4UizFUEY

Melody Gardot/"Sunset in Blue":
https://www.youtube.com/watch?v=qndrrfdmPIA&list=RDMM7_XiW7VrQSo&index=2

Astrid Gilberto/"How Insensitive" (even through translation, the words are beautiful & sad):
https://www.youtube.com/watch?v=XxVWqOdn150

My first post, Nat King Cole, That’s All.
I can only give you love that last forever 

First - Johnny Mathis was the KING of makeout music in the 50's and 60's with "Chances Are", "Wonderful, Wonderful" "Misty", "The Twelfth of Never" -  Tommy Edwards "It's All In The Game", "Please Love Me Forever", "Love Is All We Need" -  Perry Como "And I Love You So" - Paul Anka "Put Your Head On My Shoulder", "Puppy Love" - John Gary's version of "Unchained Melody" - Nat King Cole "Unforgettable" - The Lettermen "When I Fall In Love", "The Way You Look Tonight", "Portrait Of My Love".- Jesse Belvin "Goodnight My Love"